Ignition timing control means for internal-combustion engines



Aprll 11, 1950 MALLQRY 2,503,753

IGNITION TIMING CONTROL MEANS FOR v INTERNAL- COMBUSTION ENGINES FiledD90. 22, 1947 RETARD 600 I000 I400 I800 2200 SPEED REM.

INVENTOR. L Y [E- 2 MAR/ 0N MALLOI? ATTORNEYS.

Patented Apr. 11, 1950 OFFICE IGNITION TIBHNGCONTROL MEAN S FDRINTERNAL-:COMBUSTION ENGINES Marion lvlallcry, Detroit, Mich.Application December v22, 1941, Serial No. :93.093

l This invention relates to ignition timing con: trol means for aninternal combustion engine. This invention contemplates an ignitionsystem which is controlled by thepressures obtain ing in the intakepassageway of the engine so that the spark will beretarded when theengine is idling, will advance in direct relation to the engine speedwhen thethrottle is wide open. and will advance ahead of the load curveat inter mediate positions of the throttle.

' Fig. 1 is a sectional view showing the ,m'echa nism of my ignitiontiming control means for an internal combustion engine.

, Fig. 2 is a graph showing one curve for the part throttle sparkadvance and another curve for the full throttle spark advance.

Referring more particularly to the drawings there is shown a carburetor1 having an atmospheric air inlet 2, an outlet .3 to the engineintakemanifold, a throttle valve 4 of the butterfly type mounted on the usualshaft 5 iournalled in the carburetor housing, a venturi 6 having anorifice I, Another orifice .8 is located in the intake pas sagewayadjacent to, but on the atmosphereside of, throttle valve dwhen in idleposition.

The timing mechanism is conventional and, as. shown, consists of theusual rotatable cam I9 which operates the electrical circuit breakerIii. The circuit breaker ill is mounted onplate ll. which .can berotated clockwise to advance the spark and counterclockwise to retardthe spark.

Two suction devices are utilized for advancing.

and retarding the spark. One suction device 12 comprises a flexiblediaphragm is backed up by compression spring I 4. Diaphragm 13 ismounted in housing I5, the suction chamber 16 0i which is connected byconduit ll with orifice l. phra m I3 is connected to plate I I byconnecting rod I8, one end of which is pivotally connected to plate IIas at 19 and the other end of which is fixed to the diaphragm.

The other suction device, for purposes of illustration, is shown ascomprising cylinder 20, piston 2|, compression spring '22 which urgespiston 2| toward the right, and conduit 23 which connects cylinder withorifice ,8. A connecting rod-24 has a fixed pivotal connection as at 25with piston 2| and has a lost motion connectionwith plate II in the.form of pin 26 on plate I l which interengages connecting rod 24 inelongate slot 27.

The operation of my device is as follows: When the throttle valve 4 iswide open the spark advance is in direct relation to the engine speedand this spark advance is illustrated by curve A in Fig. 2. The sparkadvance at idle engine speed Dia-.

2 andpart throttle is illustrated by curve B, Fig. "2'.

InFig. 1 I have shown the throttle at idle position and the spark isretarded because the pressure at orifices "I and 8 will 'besubstantially atmospheric and the pressure in suction chamber it and.within cylinder'fl fl will also be atmospheric at such throttleposition.

When throttle 4 is wide open the venturi sue tion created at orifice "lby the velocity of the air flowing through venturi 6 will establishitself in suction chamber [5 and advance the spark in direct relation tothe engine speed, as illustrated by curve A. It should be noted that asplate II is rotated clockwise by suction device I2 to advance the sparkthat this advance is not resisted by spring-22 because pin 26 simplymoves freely or idles in elongate slot 2*! and when the spark is fullyadvanced pin 26 will be short of the left hand end of slot 21.

If the throttle is moved from idle position toward open position,orifice 8 will be placed upon the engine side of the throttle valve andthe full manifold vacuum will be applied through orifice 8, conduit 23upon piston 2i, thereby drawing the same toward the left against thepressure of spring 22. As piston 2'! is drawn toward the left, link '24contacts pin '26 and controls the spark advance, per curve 'B, Fig. 2.It should be noted that the advance of the spark is very abrupt asorifice 3 passes on to the engine side of valve -4 because the fullmanifold vacuum will be established in piston 2i Spring 22 is a strongspring but thevacuum is so high when throttle 4 is only partly open thatthe spark will advance far ahead of the load curve (that is, the curvewhich exemplifies the degree of opening of throttle valve 4). However,due to the fact that the spring '22 is a relatively strong spring, thespark will immediately retard if the throttle 4 is opened very fartoward open position, but never further than permitted by venturisuction at orifice '7 acting through suction device I2.

I claim: p

1. In an internal combustion engine having an intake passageway with aventuri and a throttle valve positioned on the engine side of said veneturi for controlling fluid flow through said passageway, an ignitiontimer, a'su'ction' device connected into the venturi, a connectionbetween the aforesaid suction device and ignition timer, a secondsuction device connected into the intake passageway adjacent ,to and onthe atmosphere side of the throttle valve when in idle position, aconnection between said second suction device and the ignition timerwhereby when the throttle valve is wide open the first mentioned suctiondevice responds to venturi suction and controls the position of saidignition timer and when the throttle is partly open the second suctiondevice responds to the suction on the engine side of the throttle valveand controls the position of said ignition timer, the said connectionbetween the second suction device and the ignition timer being a lostmotion connection whereby when the throttle valve is wide open the firstsuction device can actuate said ignition timer independently of saidsecond suction device.

2. In an internal combustion engine having an intake passageway, athrottle valve in the intake passageway, a venturi in the intakepassageway on the atmosphere side of the throttle'valve, an orifice inthe venturi, a second orifice in the intake passageway adjacent to andon the venturi side of said throttle valve when in idle position wherebythe throttle valve moves between the two orifices as it moves toward anopen position from idle thereby subjecting the second orifice to thesuction obtaining on the engine side of the throttle valve, a suctionresponsive device connected into the first orifice and a second suctionresponsive device connected into the second orifice, an ignition timer,connections between. each of the suction responsive devices and theignition timer whereby when the throttle valve is wide open the firstsuction responsive device responds to venturi suction and controls theignition spark advance substantially in direct relation to the enginespeed and when the throttle valve is partly open the second suctiondevice responds to the suction on the engine side of the throttle valveand controls the ignition spark advance in accordance with said lastmentioned suction, resilient means for moving the ignition timer toretard the spark whenever the suction falls in the first suction device,the connection between the second suction device and the ignition timerbeing a lost motion connection so that the second suction devicepositively moves said ignition timer to advancethe spark in response toan increase in suction and is inefiective to move the ignition timer toretard the spark.

3. The combination as set forth in claim 2 wherein the connectionbetween the second suction device and the ignition timer takes the formof a pin and elongate slot. 4. In an internal combustion engine havingan intake passageway provided with a throttle valve for controlling thefiow of motive fluid to the engine, a venturi in said intake passagewayon the atmosphere side of said throttle valve, an ignition timer, anorifice in said venturi, means connected into said orifice and actuatedthrough changes in the venturi suction obtaining at said orifice forimparting movement to said ignition timer, a second orifice in theintake passageway positioned adjacent to and on the atmosphere side ofsaid throttle valve when in idle position and passing on to the engineside of saidthrottle valve as it is opened 'from idle position, a secondmeans connected to said second orifice and actuated through changes inpressure in the intake passageway obtaining at said second orifice forimparting movement to said ignition timer 4 whereby when the throttlevalve is wide open the first pressure actuated means responds to venturisuction and controls the ignition spark advance substantially in directrelation to the engine speed and when the throttle valve is partly openthe second pressure actuated means responds to the suction on the engineside of the throttle valve and controls the ignition spark advance inaccordance with said last mentioned suction, a connection between thefirst pressure actuated means and the ignition timer whereby movement ofthe pressure actuated means imparts movement to the ignition timer, anda lost motion connection between the second pressure actuated means andthe ignition timer whereby movement of the second pressure actuatedmeans in a spark advance direction only moves said ignition timer.

5. In an internal combustion engine having an intake passageway providedwith a throttle valve for controlling the fiow of motive fluid to theengine, a venturi in said intake passageway. on the atmosphere side ofsaid throttle valve, an ignition timer, an orifice in said venturi,means connected into said orifice and actuated through changes in theventuri suction obtaining at said orifice for imparting movement to saidignition timer, a second orifice in the intake passageway positionedadjacent to and on the atmosphere side of said throttle valve when inidle position and passing on to the engine side of said throttle valveas it is opened from idle position, a second means connected to saidsecond orifice and actuv ated through changes in pressure in the intakepassageway obtaining at said second orifice for imparting movement tosaid ignition timer whereby when the throttle valve is wide open thefirst pressure actuated means responds to venturi suction and controlsthe ignition spark advance substantially in direct relation to theengine speed and when the throttle valve is partly open the secondpressure actuated means responds to the suction on the engine side ofthe throttle valve and controls the ignition spark advance in accordancewith said last mentioned suction, and resilient means tending at alltimes to move said ignition timer to retard the spark whereby when thethrottle is at idle position substantially atmospheric pressure obtainsin both of said prese sure actuated means and the spark is fullyretarded, said second means including a one way driving connection withsaid ignition timer whereby said second means is efiective to actuatesaid ignition timer to advance the spark when the throttle valve ispartly open and the suction at the said second orifice increases but isineffective to actuate said ignition timer to retard the spark whensaidsuction decreases.

MARION MALLORY.

REFERENCES CITED The following references are of record in the file ofthis :patent;

UNITED STATES PATENTS rm n ug-3 1

